Functional classification of the cerebellum and cerebellar ataxia: a narrative review

Ataxia is defined as impaired motor coordination, and cerebellar ataxia refers to ataxia resulting from cerebellar dysfunction. Representative clinical manifestations include oculomotor disturbances, nystagmus, truncal and gait ataxia, dysmetria, and dysdiadochokinesia, and each manifestation relates to the functional anatomy of the cerebellum, which is divided into the vestibulocerebellum, spinocerebellum, and cerebrocerebellum. Since cerebellar ataxia can be caused by various disorders, differential diagnosis is important. Based on the temporal profile of symptom onset, it can be divided into acute, subacute, chronic, and episodic cerebellar ataxia. Based on age at onset and the presence of genetic abnormalities, it can be divided into hereditary, acquired, and non-hereditary degenerative cerebellar ataxia. For a clinical approach to cerebellar ataxia, it is essential to understand cerebellar function according to anatomical and functional classification. If cerebellar ataxia is confirmed on neurological examination, it is important to identify the underlying etiology through appropriate diagnostic tests.